This circuit is from an article that appeared in the June 1974 issue of Radio Electronics magazine. The circuit used integrated circuits and transistors of the time and included the power supply.
This circuit is recommended for alarm systems since it has a good output stage. The circuit is...
) Suggested by Philips in a 1968 documentation this circuit has very high 10 ohm on-load voltage...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...